JIPMER2015PhysicsElectrostatics
Two small balls, each carrying a charge q are suspended by equal insulator strings of length 1 m from the hook of a stand. This arrangement is carried in a satellite in space. The tension in each string will be
Options
- A1 4 ₀ q l^2
- B1 4 ₀ q^2 4 l^2
- C1 4 ₀ q^2 l^2
- D1 (4 ₀ ) q l
Correct answer
B. 1 4 ₀ q^2 4 l^2
Step-by-step solution
Suppose, T be the tension in the spring T . Also in the satellite, two balls will be in a straight line. So, force acting on the balls F= 1 4 ₀ q^2 (2 l)^2 (i) This force will be balanced by tension in the string. i.e., T=F (ii) Now, from Eqs. (i) and (ii), we get T= 1 4 ₀ q^2 4 l^2